Pebdeeick w



(No Model.)

F. W. ROBINSON.

HYDRAULIC GONGENTRATOR.

No. 371,711. Patented Oct. 18,1887.

. 5 N V 814W,

rrrrrn 'rnrns Parent" rrrcnl FREDERICK IV. ROBINSON, OF SAN FRANCISCO, CALIFORNIA, ASSIG-NOR TO L. L. ROBINSON, OF SAME PLACE. I

HYDRAULIC CONCENTRATOR.

SPECIFICATION forming part of Letters Patent No. 371,711, dated. October 18, 1887.

Application filed April 11, 1387.

To all whom it may concern:

Be it known that I, FREDERICK W. ROBIN soN, of the city and county of San Francisco, State of California, have invented an Improve mentin Hydraulic Concentrators; and I hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to a novel apparatus for concentrating and separating substances of IO varying specific gravity contained in ores, earth, sands, or tailings; and it consists in the improved concentrator which I shall hereinafter fully describe and claim.

Referring to the accompanying drawing for a more complete explanation of my invention, the figure is a partial longitudinal vertical section taken through my apparatus.

A is the trunk, flume, tube,or sluice, having a tight bottom, top, and sides. The floor of the tube or sluice may be made of varying degrees of inclination, commencing at a nearly horizontal section at the lowest point and gradually increasing to any degree of steepness at the outlet; but I prefer to make it in the form of a curve having the point of greatest curvature at the outlet. The material to be separated, mixed withv water, is received into the lower end of the apparatus througha receiver, as shown at B, from a hopper or ver tical chute, 0. In order to reduce the quantity of material which must be passed through this sluice A,'I employ screens, or what are technically known as grizzlies, (not herein shown,) standing at an inclination above the hopper O. The material to be separated is received upon these screens or grizzlies from the supply flume or sluice, and the coarser mate rialwaste rock and gravel-will be diverted by these screens and discharged to one side 40 without passing into the closed tube or sluice. The finer and more valuable material will pass into the tube or sluice, and will flow through it with a velocity depending upon the pressure of the water and the inclination of the tube or 5 sluice. The pressure will be regulated by the Serial No. 234,434. (No model.)

supply and the height or head of water or the depth of the receiver or hopper O, through which it passes. I

The inclination of the apparatus maybe regulated by means of a hinged joint at E, where the material enters the lower end of the sluice.

By means of this joint the outer or discharge end may be raised or depressed, so as to vary the inclination to suit the work to be done.

The particles will be distributed along the floor or bottom of the trunk, tube, or sluice until the rising inclination will present such an obstruction aswill prevent the heavier partieles which it is desirable to retain from going any farther. Each particle will be eon- 6c trolled by a constant velocity of water, carrying it forward until an equilibrium is established between the force of the water and the resistance offered by the particle acting frictionally upon the inclined surface.

The operation is similar to the drifting of sand by the winds. The common earth, sand, and gravel will pass rapidly to the waste-out let, and the heavier materials will only climb the plane or curve of the bottom until they 7c reach the point where, as before stated, the r0 sistance offered will prevent them passing beyond.

Having thus described myinvention, what I claim as new, and desire to secure by Letters 7 Patent, is

A concentrator consisting ofa closed sluice having a constantly-incrensing inclination or curvature upward from the receiving to the discharge end, and provided with a joint or means by which the general angle of inclination may be increased or diminished, substantially as herein described.

In witness whereof I have hereunto set my hand.

FREDERICK W. ROBINSON.

WVitnesses:

J 0s. Moosna, CHAS. E. Moosnn. 

